There is a long felt need for autonomous robotic cleaning devices for dusting, mopping, vacuuming, and sweeping operations. Although technology exists for complex robots which can, to some extent, “see” and “feel” their surroundings, the complexity, expense and power requirements associated with these types of robotic subsystems render them unsuitable for the consumer marketplace.
The assignee of the subject application has devised a less expensive, battery operated, autonomous cleaning robot which operates in two modes: random and wall following. In the random bounce mode, the processing circuitry of the robot causes it to move in a straight line until the robot comes into contact with an obstacle; the robot then turns away from the obstacle and heads in a random direction. In the wall following mode, the robot encounters a wall, follows it for a time, and then returns to the random mode. By using this combination of modes, robotic theory has proven that the floor including the edges thereof is adequately covered in an optimal time resulting in a power savings.
Unfortunately, however, presently available sensor subsystems such as sonar sensors for detecting obstacles on or in the floor or for detecting the wall in order to enter the wall following mode (or to avoid bumping into the wall) are either too complex or too expensive of both. Tactile sensors are inefficient.